Concrete finishing tool



Oct. 26, 1965 c. c. LASKER 3,213,476

CONCRETE FINISHING TOOL Filed May 6, 1959 2 Sheets-Sheet 1 IN VEN TOR.

CHARLES C'. LAIS'KER fiilxca,

A T TORNEY Oct. 26, 1965 c. c. LASKER 3,213,476

CONCRETE FINISHING TOOL Filed May 6, 1959 2 Sheets-Sheet 2 INVENTOR. CHARLES c. LASKER BY N; y- 6 a 4.

A T TORNE Y United States Patent 3,213,476 CONCRETE FINISHING TOOL Charles C. Lasker, 3710 Warwick Blvd., Kansas City, Mo. Filed May 6, 1959, Ser. No. 811,492 4 Claims. (Cl. 15-2354) This is a continuation-in-part of my application Serial No. 455,439, filed September 13, 1954, now abandoned.

My invention relates to concrete finishing tools, and more particularly to such a tool that is adapted to be operated to finish concrete while the operator is in a standing position.

My improved tool is a hand tool and is particularly adapted for successively spreading, smoothing, floating and finishing concrete, cement, or other materials, containing :a binder and an aggregate.

It is :a specific purpose of my invention to provide a tool of the above mentioned character that is simple and sturdy in construction and that is so constructed and arranged that it can be used as a tool for spreading material, such as concrete, and for smoothing, floating and finishing the concrete after it has been spread, while the operator remains in a standing position, and the handle of the tool is inclined at a convenient angle for operating the same from the body portion or blade of the tool toward the operator.

Said tool comprises a sheet met-a1 body portion or blade that is of uniform curvature and thickness from the forward blunt edge thereof to the rear blunt edge thereof, with the handle secured to the concave side thereof remote from the forward edge and adjacent the rear edge and extending at such an angle with respect to the tan gent to the convex face thereof :at said forward edge that the handle will be directed or inclined toward the operator of the tool both when the tool is used for spreading purposes and when used for smoothing, floating and finishing purposes. To accomplish the purposes of the invention it is necessary that the axis of the handle extend at an angle of less than 60 to said tangent and more than 45 to said tangent, enabling the tool to be used both as a spreading tool and a smoothing, floating and finishing tool for the concrete, with the forward edge thereof directed toward the operator and the handle inclined at an angle to the vertical toward the operator so that the operator can stand in such a position as to smooth, float or finish the concrete or similar material, or to spread it without getting on the material that has already been spread or smoothed.

In ordinary concrete spreading and finishing operations, a crude spreader has been used, which was merely made of a straight edged piece of wood secured to a handle so that the concrete could be spread out after being dumped so as to provide a substantially uniform layer thereof, but this apparatus was not suited for floating, smoothing or finishing operations, and in order to smooth and finish the concrete, it has been necessary prior to my invention, to finish the concrete by the use of hand tools comprising flat bladed trowels that had handles thereon that were short and extended substantially parallel to the flat blades, making it necessary for the cement finisher to be on his hands and knees while finishing the concrete.

3,213,476 Patented Oct. 26, 1965 By the use of my invention, all these operations can be carried out successively from a standing position, because of the character of the tool comprising the long narrow blade curved so as to present a cylindrical surface to the concrete upon slightly raising the forward edge or scraping edge of the tool from the surface of the concrete, enabling the floating operation, as well lHS the smoothing and finishing operation, to be carried out while the operator is in a standing position and permitting the smoothing and finishing of a large area of the concrete at one time, greatly speeding up the operation over that possible with the tools previously used for this purpose. This is due to the fact that the blade is curved on an axis parallel to the longitudinal edges of the blade or body portion of the device and is provided with a handle that is straight and extends at such an angle as previously stated, that the curved surface of the blade or body portion can be engaged with the surface of the concrete that is to be finished or smoothed, with the handle extending an angle of about 60 to this surface, and which handle can be extended at an angle of approximately 45 to such a surface for the spreading action that is carried out prior to the smoothing and finishing action.

It has been found that, in order to be capable of carrying out the desired spreading action and also the smoothing action over a sufi'iciently large area, the body portion should be at least four times as long as it is wide and the blade or body portion should be curved through an arc of about 48, and that the axis of curvature is much nearer the end of the handle engaged with the body portion or blade than the end thereof that is engaged by the operator. It is absolutely necessary in order to obtain the floating, smoothing and finish-ing action, that it is desired to obtain by means of my too-1, that the blade be curved so that the outer or convex surface thereof is curved on the surface of a cylinder so that the curved surface will have straight line contact with the material that is being smoothed or finished so that there will be no undulations in the surface after the finishing operation has been carried out.

Under some circumstances it is desirable to apply a finishing coat of a finer texture than the concrete, to the concrete surface, this being applied in the form of a thin layer of a cement and sand mixture that does not contain any gravel or rock, or other coarse aggregate. By utilizing the rear edge of the tool for spreading this relatively thin layer on top of the layer of previously spread concrete, and using the tool with its forward edge toward the operator and the handle at an angle of about 60 to the surface to be finished, for the smoothing and finishing operation, such a finishing layer can be similar- 1y spread, smoothed and finished with my improved tool.

In order that the tool can be used for the various operations hereinbefore referred to, it is highly important that the elongated handle be rigidly attached to the metallic body portion or blade of the tool in such a manner that it will not become accidentally detached therefrom. Handles that are ordinarily tapered at their ends to fit into tapered or conical sockets are particularly inclined to become accidentally detached from the socket, and it is an important purpose of my invention to provide means for mounting the handle on the blade in such a manner that this will not occur, comprising a cylindrical split ferrule that receives a cylindrical end portion of the handle so as to tightly grip the same, the handle being driven into the ferrule to place the material of the ferrule under tension so as to firmly hold the handle in the ferrule and in operative relation to the blade or metal body portion of the tool.

Other objects and advantages of my invention will appear as the description of the drawings proceeds. I desire to have it understood, however, that I do not intend to limit myself to the particular details shown and described, except as defined in the claims.

In the drawings:

FIG. 1 is a side elevational of my improved concrete finishing tool, the handle portion being broken away and the same being shown in smoothing position with respect to a fragmentary portion of a concrete structure.

FIG. 2 is a similar view showing the tool in concrete spreading position.

FIG. 3 is a similar view showing the tool in position for spreading a finishing coating on concrete.

FIG. 4 is an inside face view of the tool, the handle being shown in section.

FIG. 5 is an enlarged fragmentary sectional view taken on the line 5-5 of FIG. 4.

'FIG. 6 is a view showing the entire tool in side elevation in full lines in spreading position and in dotted lines in smoothing position, and

FIG. 7 is a diagrammatic view to illustrate the relative angular position of the center line of the handle to the tangent to the convex surface of the blade or body portion of the tool at the forward edge thereof.

Referring in detail to the drawings, my improved concrete finishing tool has a rectangular body portion 11 of heavy gauge sheet metal having straight parallel blunt end edges 12, a straight forward blunt longitudinal edge 13 and a straight blunt rear longitudinal edge 14, said edges 13 and 14 being parallel to each other, as are the edges 12, said edges 12 extending perpendicularly to the edges 13 and 14. Said body portion 11 is long and narrow, as will be obvious from FIG. 4, being shown as being more than four times as long as it is wide.

Said body portion is curved uniformly on a circular arc from the forward edge 13 thereof to the rear edge 14 thereof to provide a smooth cylindrically curved convex face 15 thereon, which is of the same curvature from the forward edge 13 to the rear edge 14 of said body portion, and a smoothly curved concave face 16 thereon, also extending at the same curvature from the forward edge 13 to the rear edge 14 of said body portion.

Rigidly secured to the concave face 16 of said body portion 11 by means of rivets 17 or other suitable means, is a rectangular plate-like flange 18 of a cylindrical ferrule 19, which is split as shown at 20 and which is made of steel, having sufficient resiliency that the cylindrical end portion 21 of the straight elongated handle 22 of the tool will be firmly gripped thereby upon being forced into the cylindrical socket provided by the ferrule 19 so as to hold the handle 22 rigidly in position with respect to the body portion or blade 11 of the tool. As will be obvious from FIGS. 1 and 4, and FIG. 6 of the drawings, the ferrule 19 is mounted adjacent the rear longitudinal edge 14 of the body portion 11, being only slightly forwardly from said rear edge 14. The cylindrical ferrule and the cylindrical handle, without any taper thereto at the end thereof adjacent the body portion that enters the ferrule, are provided to obtain a tighter grip between the ferrule and the handle, as is necessary in order that the handle be rigidly held in position in the body portion.

When the tool is used for finishing or smoothing purposes, as illustrated in FIG. 1 of the drawings and in dotted lines in FIG. 6, the forward edge 13 is very slightly raised above the surface of the concrete body 23, which is shown as having been finished by the tool in the portion 24 thereof and in unfinished condition in the portion 25 thereof. The axis of the cylindrical ferrule 19 and thus of the handle 22, extends at such an acute angle to the tangent to the outer convex face 15 of the body portion 11 at the forward edge 13 thereof that, when so used, the axis of the ferrule 19 and of the handle 22 will be extending at an angle of approximately 60 to the horizontal or the finished surface 24, which is a suitable angle for easy manipulation of the tool by the operator in a standing position, who will be having his hands in engagement with the handle 22 adjacent the upper end portion thereof, the convex surface 15 to the rear of the edge 13 doing the smoothing or finishing operation as the tool is moved from left to right as shown in FIG. 1.

When the tool is used for spreading the concrete prior to the finishing thereof, the tool is used in substantially the position shown in FIG. 2, in which a fragmentary portion of the dumped mass is shown at 26, which has been partially spread as shown at 25 in said figure. The axis of the socket 19 and handle 22 with respect to the horizontal will be varied somewhat during the spreading operation, but will have an average or mean position of about 45 to the horizontal. In this position of the tool the forward edge 13 is utilized for spreading purposes.

It is sometimes desirable to apply a finishing coat of a finer texture, usually made up of only cement and sand, to the concrete body 23, said finishing coat being shown at 27 in FIG. 3, and being shown as having been spread from a dumped mass thereof, indicated at 28, so as to provide a substantially uniform thickness thereof, as indicated at 29 in FIG. 3. The spreading of said finishing ply or layer is accomplished by means of the rear longitudinal edge 14 of the tool by reversing the same from the position shown in FIG. 2 to that shown in FIG. 3, the position of the ferrule 19 and handle 22 relative to the edge 14 preventing too deep digging into the finishing ply 27 during this spreading operation. After the finishing coat 27 has been spread as shown at 29 in FIG. 3, it is finished in the same manner as illustrated in FIG. 1, by again turning the body portion of the tool to the position shown in FIG. 1 with the forward edge 13 thereof raised so that the convex surface 15 thereof slightly back of the edge 13 will glide over the surface of the finishing coat 27 and smooth it. It will be noted that during these smoothing operations or finishing operations, the cylindrically curved convex surface 15, which is of the same curvature from one end 12 to the other end 12 of the tool, will present a straight edge engaging with the surface of the concrete or top coating that is being finished so that it will be flat and have no undulations therein, as would be the case if any other than a cylindrical surface were presented to the concrete during this smoothing operation.

The preferred angle of the axis of the ferrule 19 and the handle 22 to the tangent to the convex outer face 15 of the body portion 11 at the forward edge 13 is approximately 55, as with this angularity of the axis of the handle, the handle will extend at an angle of 60 to the surface that is being smoothed while the tool is in the operative position shown in FIG. 1. Also the axis of the cylindrical ferrule 19 and thus of the handle 22, will extend at such an angle when the tool is used for spreading the material that the concave face of the body portion engaging with the concrete to spread it, as will be obvious from FIG. 2, will ride up on the concave face and the forward edge 13 will dig into the body of concrete 26 that is being spread, the digging action taking place by a mere pulling action on the handle 22, avoiding the necessity of any pushing downwardly on the handle to cause the body portion or blade to enter the concrete sufficiently to spread it, as is necessary with tools that have flat faces or plane faces thereon that are used for this purpose. This makes it possible to work much more rapidly and with much more ease in spreading the concrete with the tool than with the ordinary fiat faced spreading tool. This is due to the concave character of the body portion of the tool as well as to the locationof the handle near the rear edge of the body portion and its angular relationship to the tangent to the curve of the body portion above referred to.

The radius of curvature of the cylindrically curved blade is very short with relation to the length of the handle 22, being preferably less than one-twelfth of the length of the handle, thus placing the center of curvature closely adjacent the end of the handle that is engaged in the ferrule. It has been found that an arc of approximately 48 is desirable for the blade or body portion 11. It will also be noted that the axis of the handle extends radially of the curved blade or body portion 11. In FIG, 7 the relationship of the curvature of the blade and the axis of the handle is indicated diagrammatically. The tangent to the blade at the forward edge 13 thereof is in dicated by the line G in FIG. 7, the axis of the handle by the line H and the center of curvature of the blade by the point C, the curvature of the blade being indicated by the curved line B. The relationship of the axis of the handle to the tangent to the curve of the convex face of the blade at its forward edge is such that when the tool is used for smoothing, floating and finishing purposes, as illustrated in FIG. 1, the forward edge 13 of the tool will be raised above the surface of the concrete so that it will not dig into the same and the inclination of the handle toward the operator, who would have to be located to the right of the edge 13 as viewed in FIG. 1, in order not to walk on the smoothed, floated or finished concrete, will be such that the operator of the tool will be able to conveniently carry out the floating, smoothing and finishing operations in a standing position. In floating concrete, the tool is given an up and down or tamping motion, ininstead of a spreading motion, as in the smoothing or finishing operation, but in either case it is highly desirable and necessary that only the convex face engages with the concrete and that the forward edge 13 will be raised sufficiently so as to not dig into the concrete. Furthermore the edge 13 and the edge 14 are left blunt so that there will be no tendency of these edges to dig into the concrete when this is not desired. When used for spreading, the convex face will not have any tendency to drag in the material as would the flat face of a tool, such as has been commonly used for this purpose, the body portion curving away from the concrete, that has been spread on the convex side 15 of the blade, as is obvious from FIG. 2. The same thing holds true when spreading of the finishing coat is carried out as shown in FIG. 3.

What I claim is:

1. A concrete finishing tool having a long narrow rectangular rigid sheet metal body portion of uniform thickness throughout its area, said body portion being transversely curved on a smooth curve from one longitudinal edge to the other longitudinal edge thereof about an axis parallel to its length on an arc of a circle of fixed predetermined radius to provide a concave face on one side thereof and a convex cylindrically curved face on the other side thereof extending continuously throughout the length of said body portion to provide a smooth convexly cylindrically curved concrete finishing surface on said convex face extending continuously from end to end thereof, said body portion having straight end edges, a straight blunt forward longitudinal edge extending from one end edge thereof to the other end edge thereof and a straight blunt rear longitudinal edge extending from one end edge thereof to the other end edge thereof, and an elongated straight handle rigidly secured in fixed position to said body portion on the concave face thereof remote from the forward longitudinal edge and adjacent but spaced inwardly from said rear longitudinal edge of said body portion midway of the length thereofand extending forwardly from said concave face at an angle of between 45 degrees and 60 degrees to a tangent to the convex face of said body portion at said forward edge.

2. A concrete finishing tool having a long narrow rectangular rigid sheet metal body portion of uniform thickness throughout its area, said body portion being not more than one-fourth as wide as it is long and being transversely curved on a smooth curve from one longitudinal edge to the other longitudinal edge thereof about an axis parallel to its length on an arc of a circle of fixed predetermined radius to provide a concave face on one side thereof and a convex cylindrically curved face on the other side thereof extending continuously throughout the length of said body portion to provide a smooth convexly cylindrically curved concrete finishing surface on said convex face extending continuously from end to end thereof, said body portion having straight end edges, a straight blunt forward longitudinal edge extending from one edge thereof to the other end edge thereof and a straight blunt rear longitudinal edge extending from one end edge thereof to the other end edge thereof, and an elongated straight handle rigidly secured in fixed position to said body portion on the concave face thereof remote from the forward longitudinal edge and adjacent but spaced inwardly from said rear longitudinal edge of said body portion midway of the length thereof and extending forwardly from said concave face at an angle of between 45 degrees and 60 degrees to a tangent to the convex face of said body portion at said forward edge.

3. A concrete finishing tool having a long narrow rectangular rigid sheet metal body portion of uniform thickness throughout its area, said body portion being transversely curved on a smooth curve from one longitudinal edge to the other longitudinal edge thereof about an axis parallel to its length on an arc of a circle of fixed predetermined radius to provide a concave face on one side thereof and a convex cylindrically curved face on the other side thereof extending continuously throughout the length of said body portion to provide a smooth convexly cylindrically curved concrete finishing surface on said convex face extending continuously from end to end thereof, said body portion having straight end edges, a straight blunt forward longitudinal edge extending from one end edge thereof to the other end edge thereof and a straight blunt rear longitudinal edge extending from one end edge thereof to the other end edge thereof, a cylindrical split ferrule rigidly secured to said body portion and projecting from the concave face thereof adjacent but spaced inwardly from said rear edge of said body portion, said ferrule having its axis extending at an angle of between 45 degrees and 60 degrees to a tangent to the convex face of said body portion at said forward edge, and an elongated straight handle having a cylindrical end portion mounted in said ferrule to rigidly mount said handle on said body portion in fixed position with its axis coinciding with the axis of said ferrule.

4. A concrete finishing tool having a long narrow rectangular rigid sheet metal body portion of uniform thickness throughout its area, said body portion being transversely curved on a smooth curve from one longitudinal edge to the other longitudinal edge thereof about an axis parallel to its length through a fixed circular arc of approximately 48 degrees to provide a concave face on one side thereof and a convex cylindrically curved face on the other side thereof extending continuously throughout the length of said body portion to provide a smooth convexly cylindrically curved concrete finishing surface on said convex face extending continuously from end to end thereof, said body portion having straight end edges, a straight blunt forward longitudinal edge extending from one end edge thereof to the other end edge thereof and a straight blunt rear longitudinal edge extending from one end edge thereof to the other end edge thereof, and an elongated straight handle rigidly secured in fixed position to said body portion on the concave face thereof remote from the forward longitudinal edge and adjacent but spaced inwardly from said rear longitudinal edge of said body portion midway of the length thereof and extending forwardly from said concave face at an angle of between 45 degrees and 60 degrees to a tangent to the convex face of said body portion at said forward edge.

References Cited by the Examiner UNITED STATES PATENTS 1,593 4/40 Homer 172-381 219,765 9/79 Reese 172-371 323,130 7/85 Ells 172-371 474,121 5/92 Gayon 15-236 XR 1,008,873 11/11 Stults 172-375 1,339,222 5/20 Randall 172-375 1,659,944 2/28 Dome 172-381 8 Zinn 15-1055 Fanberg 94-45 Abram 15-2358 Giardello 172-372 FOREIGN PATENTS Great Britain. Great Britain. Sweden.

CHARLES A. WILLMUTH, Primary Examiner. CORNELIUS D. ANGEL, SIDNEY JAMES, Examiners. 

1. A CONCRETE FINISHING TOOL HAVING A LONG NARROW RECTANGULAR RIGID SHEET METAL BODY PORTION OF UNIFORM THICKNESS THROUGHOUT ITS AREA, SAID BODY PORTION BEING TRANSVERSELY CURVED ON A SMOOTH CURVE FROM ONE LONGITUDINAL EDGE TO THE OTHER LONGITUDINAL EDGE THRREOF ABOUT AN AXIS PARALLEL TO ITS LENGTH ON AN ARC OF A CIRCLE OF FIXED PREDETERMINED RADIUS TO PROVIDE A CONCAVE FACE ON ONE SIDE THEREOF AND A CONVEX CYLINDRICALLY CURVED FACE ON THE OTHER SIDE THEREOF EXTENDING CONTINUOUSLY THROUGHOUT THE LENGTH OF SAID BODY PORTION TO PROVIDE A SMOOTH CONVEXLY CYLINDRICALLY CURVED CONCRETE FINISHING SURFACE ON SAID CONVEX FACE EXTENDING CONTINUOUSLY FROM END TO END THEREOF, SAID BODY PORTION HAVING STRAIGHT END EDGES, A STRAIGHT BLUNT FORWARD LONGITUDINAL EDGE EXTENDING FROM ONE END EDGE THEREOF TO THE OTHER END EGDE THEREOF AND A STRAIGHT BLUNT REAR LONGITUDINAL EDGE EXTENDING FROM ONE END EDGE THEREOF TO THE OTHER END EDGE THEREOF, AND AN ELONGATED STRAIGHT HANDLE RIGIDLY SECURED IN FIXED POSITION 